graniodioriitti

Granodiorite is an intrusive igneous rock of intermediate composition. It is characterized by its granular, phaneritic texture, meaning its crystals are large enough to be visible to the naked eye. The mineral composition of granodiorite is primarily quartz, plagioclase feldspar, and biotite or hornblende. The proportion of quartz is generally between 20% and 60% of the total feldspar content, with plagioclase feldspar being more abundant than alkali feldspar. This mineralogy distinguishes it from granite, which has a higher proportion of alkali feldspar.

Granodiorite forms from the slow cooling and solidification of magma deep beneath the Earth's surface. This slow cooling allows for the formation of large, interlocking crystals. It is a common rock type found in continental crust and is often associated with the cores of mountain ranges. Its formation is frequently linked to convergent plate boundaries, where tectonic plates collide and magmas are generated.

The rock typically appears as a gray or salt-and-pepper speckled rock due to the presence of both light-colored feldspars and darker minerals like biotite and hornblende. Its durability and resistance to weathering make it a valuable building material, historically used in construction for monuments, buildings, and sculptures. Many famous geological formations and batholiths are composed largely of granodiorite.